A method of the type described in the opening paragraph is known from JP-A-60/74330. In the method described therein, use is made of a (hollow) managing tool comprising a tubular portion and a gradually widening portion. The tubular portion of the managing tool is introduced into the neck portion, after which the electron gun is accommodated in the wide end portion of the managing tool, so that the resilient elements bear against the inner wall of the managing tool. The electron gun is slid through the managing tool into the neck portion. In this operation, the resilient elements are urged towards each other by the shape of the managing tool, as a result of which the electron gun can be more easily inserted into the neck portion and it is preluded that the resilient elements scratch the end portion and the inner wall of the neck, which would cause glass particles to be released.
It has been found, however, that despite the use of these measures, a still significant number of the manufactured cathode ray tubes is rejected. It has also been found that in several finished cathode ray tubes the mutual positioning of the electrodes in the electron gun does not meet the requirements.